Predictions of a future with even more extreme weather in Toronto should be taken seriously, if only as a precaution, says a climate change skeptic at city hall, as others suggested the municipality may have to spend billions of dollars rejigging its infrastructure.

The parks and environment committee unanimously agreed to set up a working group to examine the “increasingly wet and volatile climate” described in Toronto’s $250,000 Future Weather and Climate Driver study. Among its most alarming predictions for 2040 to 2049: The number of days when the Humidex exceeds 40C will increase fourfold; an average of 0.57 heat waves will jump to five a year; and Toronto will see 26 fewer snow days, and more rain than snow, during the winter.

“Over the next generation we’re going to have to spend billions of dollars rejigging our infrastructure,” Councillor Gord Perks said. “Our infrastructure is built for a city in a different climate than the one our children are going to live in.”

Councillor Norm Kelly, chair of the parks and environment committee, endorsed the working group, but was not entirely convinced by the science. He accused Mr. Perks — who ominously predicted “people will die” as a result of climate change in Toronto — of being alarmist.“We interpret the past but we imagine the future,” said Mr. Kelly, adding that if Toronto ends up feeling like Tennessee, “that ain’t bad.” He remains skeptical, however, of “the degree to which the climate is changing and what lies ahead.

“I think there is information coming along the academic pipeline that suggests that there is a complexity to the issue that has yet to be fully understood,” Mr. Kelly said, adding “healthy skepticism” is important if it will cost billions of dollars for an infrastructure overhaul. Still, he said, the city should take the report “seriously,” decide whether it’s an accurate assessment and determine how to prepare.

According to city data, a one-hour storm in 2005 cost $47-million in repairs — including the washout and reconstruction of Finch Avenue at Black Creek — and cost the insurance industry $600-million in payments.

The study also predicts that by 2040 to 2049, Toronto’s average annual temperature will rise by 4.4C, with winter temperatures going up on average by 5.7C and the summer thermometer jumping 3.8C.

James Young, a senior air quality and weather specialist with SENES Consultants who conducted the study, told politicians the essence of climate change is not global warming — it’s change.

“One of the mistakes that we scientists made early on in studying climate change is we let the people who sell these programs convince us to use the term global warming. And that’s a misnomer. Some places will get warmer, and some places will get colder,” Mr. Young said.

Councillor James Pasternak, meanwhile, urged his colleagues not view the debate in ideological terms.

“I’ve been caught in some really nasty storms and my daughter is living down in New York City. She’s only been there two-and-a-half years, and she’s had a massive snowstorm, a tornado and a hurricane. These are facts, these are facts on the ground. You cannot deny them,” Mr. Pasternak said. “Whether this is the set for The Day After Tomorrow and the Hollywood blockbuster, I think not.”